Bag



Sept. 15, 1959 s, o o ETAL 2,904,241

BAG

Filed Sept. 3, 195'! United States assignors to Bemis. Bro. Bag Company,St. Louis, a corporation of Missouri Application September '3, 1957',Serial No. 681,750 6 Claims. (Cl. 229--62.5)

Alat, Mo.,

This invention relates to bags, and more particularly to a multiwallpasted valve bag of a type used for packaging finely divided material,such as Portland cement, the bag being filled by inserting afillingspout in the valve and delivering the finely divided materialthrough the spout into the bag.

Among the several objects of the invention may be noted the provision ofa multiwall pasted valve bag having an improved closure construction atthe corner of the bag opposite the valve which effectively prevents thefinely divided material from blowing in. between the bag plies at saidcorner; the provision of such a construction which avoidsundue-stiffening of the pasted closure at said corner; and the provisionof a bag with a closure construction such as described which is strongand economical to manufacture. Other objects and features, will be inpart apparent and in part pointed out hereinafter;

The invention accordingly comprises the constructionshereinafterdescribed, the scope of the invention being in:v dicated in thefollowing claims.

In the accompanying drawings, in which one of various, possibleembodiments of the invention is illustrated,

Fig. 1 is a perspective view of a mul'tiwa'll paper bag tube from whicha multiwall bag of this invention is made, the tube being shown asspread open to some extent rather than in its normally fiat condition;

Fig. 2 is a view of the insideof the lowerleft corner of the bag withthe corner spread open, taken on line 22 of Fig. l;

Fig. 3 is a view in elevation showing astep in the formation of pastedtop and bottom closures on the Fig. 1 tube; and,

Fig. 4 is a view in elevation of a completed bag.

Corresponding reference characters indicate corre sponding partsthroughout the several views of the drawings.

Referring to the drawings, Fig. 1 shows a flat multiwall paper bag tube1 from which a multiwall bag of this invention is made. As shown, thistube is a four-ply tube, its inner ply being designated 3, the next twoplies 5 and 7, and the outer ply 9 (see Figs. 1 and 2'). The side foldsof the flat tube 1, which constitute its side edges, are designated 11and 13. As herein illustrated, a. valve is to be provided at the topright corner of the tube as viewed in Fig. 1. The tube is provided atthis corner with a relatively short integral extension 15 of all fourplies of the tube. This extension is centrally folded on a fold which iscoincident with the right side fold 13 of the tube. When unfolded flat,the extension 15 has a total width somewhat greater than the width ofthe pasted end closure which is to be formed at the upper end of thetube 1.

At the lower right corner of the tube (-as illustrated in Fig. 1) thereis a cutout 17. It will be understood that bag tubes such as the tube 1shown in Fig. l are manu-.

factured in commercial production by segmenting a continuous length ofbag .tubing into. individual tubes 1.

One way of providing extension 15' on each of the tubes 1 segmented fromthe continuous length of tubing is to cut the material for the extension15 of any given tube 1 out of the adjacent end of the adjacent tubesegmented fromthe continuous length of tubing. This leaves cutout 17 atthe other end of each tube from the end with the extension 15 (see Fig.1).

The tube 1 is provided at its upper end adjacent the valve corner withlongitudinal slits 19 defining an end closure flap 21 for the right(valve) end of the bag top. The tube 1 is further provided adjacent thecorner opposite the valve corner (the upper left corner as viewed inFig. 1) with longitudinal slits 23 defining end closure flap '25 for theother end of the bag top. At its lower end, the tube is providedadjacent the corner having the cutout 17 with longitudinal slits such asindicated at 27 defining end closure flap 29 for the right end of thebag bottom, and adjacent the other lower corner with longitudinal slitssuch as indicated at 31 defining end closure flap 33 for the other endof the bag bottom.

At its upper end, the tube is provided at the corner opposite the valvecorner with a relatively long extension- 35 of the inner ply 3 only andwith. a cutout or notch 37 in the outer ply only. The extension 35 andcutout 37 are of approximately the same width, this being at least equalto the width of the top closure which is to be formed but less than thewidth of the inner end edge of the end flap 25 (which is determined bythe distance between the slits 23 measured around the upper margin ofthe bag)- The cutout 37 exposes a portion 39 of the ply 7 which liesunder the outer ply.

At the lower left corner of the tube (as illustrated in Figs. 1 and 2),there is a cutout or notch 41 in the inner ply 3 having the same outlineas the extension 35 and an extension 43; of the outer ply 9 having thesame outline as the cutout 37. As previously stated, it will beunderstood that bag tubes such as the tube 1 shown in Fig. 1 aremanufactured in commercial production by segmenting a continuous lengthof bagv tubing into individual tubes 1. One way of providing extension35' on the inner ply of each of the tubes- 1 segmented from thecontinuous length of tubing is to cut the material for the extension 35of any given tube 1 out of the adjacent end of the inner ply of theadjacent tube segmented from the continuous length of tubing. Thisleaves cutout 41 in the inner ply at the other end of each tube from theend with the extension 35 (see Figs. 1 and 2). Similarly, one way ofproviding notch 37 in the outer ply of each of the tubes 1 segmentedfrom the continuous length of tubing is to cut the notch in the outerply of each tube, the material bounded by the cut forming extension 43on the adjacent end of the outer :ply of the adjacent tube segmentedfrom the continuous length of tubing.

In forming the closure at the valve end of the bag tube (its upper endas illustrated), a side flap 45 is folded back upon the tube upon a foldline 4-7 extending transversely with respect to the length of the tube.This operation effects turning in of the end flaps 21 and 25, theseflaps folding on lines indicated at 49 and 51 extending from the sideedges of the tube to the inner ends of the slits 19 and 23. Upon turningin the flap 25, the extensions 35 of the inner ply is opened and spreadflat. Adhesive (paste), designated A, is then applied in the pattern.

shown in Fig. 3, the pattern consisting of a stripe of adhesiveextending transversely across the side flap 45 andthe tube from sideflap 45 and over the inner end of the end flap 25 and the extension 35to the upper end edge of the bag tube. A side flap 53 is then foldedover upon a transverse fold line 55 to overlie the end flaps 21 and 25.To complete the formation of the closure, the side flap 45 is thenfolded over upon a transverse fold line 57 to overlap the flap 53. Foldline 55 is within one side 3 edge 59 of the extension 35; fold line 57is Within the other side edge 61 of the extension 35. Portions 21a and25a of the end flaps 21 and 25 lying outward of line 55 are folded overwith and included in side flap 53; portions 21b and 25b of the end flapslying outward of line 57 are folded over with an included in side flap45.

In forming the closure at the bottom of the bag tube, a side flap 65 isfolded back upon the tube upon a fold line 67 extending transverselywith respect to the length of the tube. This operation effects turningin of the flaps 29 and 33, these flaps folding on lines indicated at 69and 71 extending from the side edges of the tube to the inner ends ofthe slits 27 and 31. Upon turning in the flap 33, the extension 43 ofthe outer ply is opened and spread fiat. Adhesive (paste), designated B,is then applied in the pattern shown in Fig. 3, the pattern consistingof a stripe of adhesive extending transversely across the as yetunfolded end portion of the tube and stripes extending in lengthwisedirection with respect to the tube from the transverse stripe and overthe inner ends of the end flaps 29 and 33 (including the extension 43)to the side flap 65. The side flap 65 is then folded over upon atransverse fold line 73 to overlie the end flaps 29 and 33. To completethe formation of the closure, at side flap 75 is then folded over upon atransverse fold line 77 to overlap the flap 65. Fold line 73 is withinone side edge 79 of the extension 43; fold line 77 is within the otherside edge 81 of the extension 43. Portions 29a and 33a of the end flaps29 and 33 lying outward of line 73 are folded over with and included inside flap 65; portions 29b and 33b of the end flaps lying outward ofline 77 are folded over with and included in side flap 75.

As a result of the above operations, and with respect structions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

We claim:

1. A multiwall paper bag having at least three plies and provided at itsends with closures, one of said closures comprising inwardly directedend flaps, a first side flap folded over on a transverse fold line tooverlie the end flaps, and a second side flap folded over on a transverse fold line to overlie the first side flap, one of the end flaps ofsaid one closure having a centrally located inwardly directed extensionof the inner ply only, and a cutout in the outer ply, said extensionhaving a width at least equal to that of said one closure but less thanthat of the inner end edge of said one end flap, the first side flap ofsaid one closure being adhered to the extension and adhered to theportion of the next to the outer ply exposed in the cutout, the sideflaps being adhered together but being free of the other end flap ofsaid one closure to provide a valve.

2. A multiwall paper bag having at least three plies and provided at itsends with pasted closures, each comprising inwardly directed end fiaps,a first side flap folded over-on a transverse fold line to overlie theend flaps, and a second side flap folded over on a transverse fold lineto overlie the first side flap, one of the end flaps at one end of thebag having a centrally located inwardly directed extension of the innerply only, and a cutout in the outer ply, said extension and said cutouthaving a width at least equal to that of the closure but less than thatof the inner end edge of said one end flap, the first side flap at saidone end of the bag being pasted to the extension and to the top closure,the side flap 53 becomes adhered to the end flap 25, to the exposedportion 39 of ply 7 in end flap 25, and to the extension of the innerply included in the end flap 25. It does not, however, become adhered tothe end flap 21. The side flap 45 becomes adhered to the side flap 53.The completed closure comprises the inwardly directed end flaps 21 and25 and the side flaps 53 and 45 folded over on the transverse fold lines55 and 57 to overlap one another and to overlie the end flaps. The edgesof all the plies in the side flaps 53 and 45 are in register. The sideflaps 53 and 45 are adhered together by the stripe of paste initiallyapplied to extend transversely across the flap 45. The adheredtogetherside flaps 53 and 45 are free of the end flap 21 to provide a valvecapable of accepting a filling spout inserted as indicated by the arrowS in Fig. 4. The flap 53 and the extension 35 of the inner ply at thecorner opposite the valve are adhered together, accomplishing the dualresult of preventing finely divided material delivered through the spoutfrom blowing in between the plies of the bag at the corner opposite thevalve and securing the flap 53 to the inner ply to strengthen theclosure without any requirement for heavy inter-ply pasting at saidcorner. Also, the flap is adhered to the portion 39 of the intermediateply 7 exposed in the cutout 37 for closurestrengthening purposes(without undue stiffening of the closure at said bag corner).

As a result of the above operations, and with respect to the bottomclosure, the side flap 65 becomes adhered to the end flaps 29 and 33,and the side flap 75 becomes adhered to the side flap 65. The completedbottom closure comprises the inwardly directed end flaps 29 and 33 andthe side flaps 65 and 75 folded over on the transverse fold lines 73 and77 to overlap one another and to overlie the end flaps. The edges of allthe plies in the side flaps 65 and 75 are in register. The side flaps 65and 75 are adhered together by the stripe of paste initially applied toextend transversely across the flap 75.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above CO!!- pastedto the portionof the next to the outer ply exposed in the cutout, the side flaps atsaid one end of the bag pasted together 'but being free of the other endflap at said one end of the bag to provide a valve, the end flap at theother end of the bag from said one end flap having an extension of itsouter ply. and a cutout in its inner ply corresponding to the cutout andextension of the firstmentioned end flap.

3. A multiwall paper bag having at least three plies and provided at itsends with closures, one of said closures comprising inwardly directedend flaps defined by longitudinal slits at the respective end of thebag, a first side flap folded over on a transverse fold line to overliethe end flaps, and a second side flap folded over on a transverse foldline to overlie the first side flap, one of the end flaps of said oneclosure having a centrally located inwardly directed extension of theinner ply only, and a cutout in the outer ply, said extension and saidcutout having a Width at least equal to that of the closure but lessthan that of the inner end edge of said one end flap as defined by theslits which define said one end fiap,

said extension and cutout being of approximately equal width, saidtransverse fold lines being located within the side edges of theextension, the first side flap of said one closure being adhered to theextension and adhered to the portion of the next to the outer plyexposed in the cutout, the side flaps being adhered together but beingfree of the other end flap of said one closure to provide a valve. 7

4. A multiwall paper bag having at least three plies and provided at itsends with pasted closures, each comprising inwardly directed end flapsdefined by longitudinal slits at the respective end of the bag, a firstside flap folded over on a transverse fold line to overlie the endflaps, and a second side flap folded over on a transverse fold line tooverlie the first side flap, one of the end flaps at one end of the baghaving a centrally located inwardly directed extension of the inner plyonly, and a cutout in the outerply, said extension and said cutouthaving awidth at least equal to that of the closure but said extensionand cutout being of approximately equal width, said transverse foldlines of the closure at said one end of the bag being located within theside edges of the extension, the first side flap at said one end of thebag being adhered to the extension and adhered to the portion of thenext to the outer ply exposed in the cutout, the side flaps at said oneend of the bag being pasted together but being free of the other endflap at said one end of the bag to provide a valve, the end flap at theother end of the bag from said one end flap having an extension of itsouter ply and a cutout in its inner ply corresponding to the cutout andextension of the first-mentioned end flap.

5. A multiwall paper bag having at least three plies and provided at itsends with closures, one of said closures comprising inwardly directedend flaps defined by longitudinal slits at the respective end of thebag, a first side flap folded over on a transverse fold line to overliethe end flaps, and a second side flap folded over on a transverse foldline to overlie the first side flap, the edges of all the plies in theside flaps being in register, one of the end flaps of said one closureshaving a centrally located inwardly directed extension of the inner plyonly, and a cutout in the outer ply, said extension and said cutouthaving a width at least equal to that of the closure but less than thatof the inner end edge of said one end flap as defined by the slits whichdefine said one end flap, said extension and cutout being ofapproximately equal width, said transverse fold lines being locatedwithin the side edges of the extension, the first side flap of said oneclosure being adhered to the extension and adhered to the portion of thenext to the outer ply exposed in the cutout, the side flaps beingadhered together but being free of the other end flap of said oneclosure to provide a valve.

6. A multiwall paper bag having at least three plies and provided at itsends with pasted closures, each compris ing inwardly directed end flapsdefined by longitudinal slits at the respective end of the bag, a firstside flap folded over on a transverse fold line to overlie the endflaps, and a second side flap folded over on a transverse fold line tooverlie the first side flap, the edges of all the plies in the sideflaps being in register, one of the end flaps at one end of the baghaving a centrally located inwardly directed extension of the inner plyonly, and a cutout in the outer ply, said extension and said cutouthaving a width at least equal to that of the closure but less than thatof the inner end edge of said one end flap as defined by the slits whichdefine said one end flap, said extension and cutout being ofapproximately equal width, said transverse fold lines of the closure atsaid one end of the bag being located within the side edges of theextension, the first side flap at said one end of the bag being adheredto the extension and adhered to the portion of the next to the outer plyexposed in the cutout, the side flaps at said one end of the bag beingpasted together but being free of the other end flap at said one end ofthe bag to provide a valve, the end flap at the other end of the bagfrom said one end flap having an extension of its outer ply and a cutoutin its inner ply corresponding to the cutout and extension of thefirst-mentioned end flap.

References Cited in the file of this patent UNITED STATES PATENTS2,346,292 Coty Apr. 11, 1944 2,668,003 Jones Feb. 2, 1954 2,729,387Brady et al. I an. 3, 1956 2,810,509 Gelbcke Oct. 22, 1957

